A recognized problem with firearms is that they can be accidentally discharged to cause serious injury or death to persons nearby. For this reason, it is customary for owners of firearms to lock same in special cabinets or other containers whereupon they are only taken out for use. However, firearms are often stored in places which either cannot be locked, or it would be inconvenient to do so. For safety purposes, guns should not be stored with cartridges in their chambers, or even in their magazines, and almost all firearms incorporate safety features. Still, there are a number of accidental injuries and deaths that occur on a continuing basis due to "unloaded" guns.
A common type of apparatus used for preventing firearms' accidental discharges are trigger locks. Unfortunately, trigger locks do not always prevent the trigger from being pulled (or pushed) and, in any event, a firing pin can often be tripped irrespective of the presence of a trigger lock on a semi-automatic firearm. Further, trigger locks are awkward and difficult to install. Thus, whereas trigger locks may be worthwhile safety equipment for some firearms, they are not a complete answer, because accidental discharge of firearms in spite of their installation thereon is frequently possible.
A further solution that has been proposed constitutes plug-in types of locking devices. For example, PCT Patent Publication No. W090/04148, of Apr. 19, 1990, of Paterson, discloses a lock for a revolver which is inserted into one of the chambers of the cylinder when the cylinder is in an open position, and is then expanded and locked in the expanded condition to prevent its withdrawal from the cylinder. As long as the cylinder cannot therefore be closed, the revolver cannot be discharged. Another firearm safety device is disclosed in the Federal Republic of Germany's Offenlegungsschrift No. 2920679, of Troedsson, published Nov. 29, 1979, which discloses a plug-in safety lock for cartridge case openings of firearms. Disclosed is a body which can be inserted into the ejection port of a firearm and which is provided at least one piston telescopically received within the body which can be extended therefrom into the cartridge chamber. In this manner, the plug-in safety lock cannot be removed through the ejection port, and the firing pin is effectively prevented from moving more than a limited amount towards the chamber. This is accomplished either by a rack and pinion arrangement, which can be locked in two settings, or by use of an eccentric pin which cooperates with a biased cam groove to move a plug on one side outwardly for locking the device in place and inwardly for being removed from the firearm involved. However, the Troedsson plug-in safety lock is designed apparently primarily for rifles, and its extendibility, when inserted within the ejection port, is limited which, in turn, limits its usefulness for handguns, wherein the amount of expandability may spell the difference between an effective lock and a lock which may be removed with the exertion of only moderate force.
U.S. Pat. No. 3,089,272, to McKenlay, of May 14, 1963, is directed to a locking type safety breech plug for firearms. The breech plug comprises a fixed rear nose and a forward sliding plunger which is actuated by the user's finger after insertion of the breech plug into the ejection port of the firearm. A key is actuated to lock the plunger in its extended position. It is to be understood that the key does not actuate the plunger and therefore two operations are required, the locking operation being effected after actuating the plunger into its desired position in the firearm. Effectively this requires two hands, one exerting a rearward force to maintain the nose against the rear inner wall of the ejection port, and the other exerting a forward force to slide the plunger manually into the forward portion of the ejector port. The installation is therefore awkward and also difficult in view of the need to hold the firearm at the same time.
A locking safety device for firearms is also disclosed in U.S. Pat. No. 3,018,576, to Riechers, of Jan. 30, 1962. The device is box-shaped and relatively large, whereby it is not readily portable by the owner or user of the firearm. The installation of the device is such that most of the device is situated outside the receiver of the firearm so that it is more susceptible to tampering than otherwise would be the case. The Riechers' device comprises a single sliding component having a limited distance of travel whereby, in effect, the device will not generally be useful for more than one or a few models of firearms. This is particularly true because its exterior contour matches that of the firearm and, accordingly, the device almost of necessity has to be of a different configuration for different models of firearms.
U.S. Pat. No. 4,266,356, to Jarvinen, of May 12, 1981, discloses a non-movable chamber plug in combination with a locking mechanism that fits into a recess of a receiver, such as a bolt lug recess. Here, as with Riechers' device discussed above, due to variations in the configurations of different models of firearms, including in particular the receivers, it is difficult to conclude that this device will fit more than one model of specific firearms.
Another U.S. Patent of interest is No. 3,634,963, to Hermann, of Jan. 18, 1972, which discloses a locking device that is placed into the ejection port of a firearm. The device is locked by a key and includes an extensible member on one side that, in cooperation with a permanent biased member on the other side, holds the lock in place. The same inventor, Hermann, discloses in another U.S. Pat. No. 3,605,311, of Sep. 20, 1971, a removable firearm lock which is insertable in a firearm ejection port having a latch operated by a key on one side of the lock.
A trigger lock is disclosed in U.S. Pat. No. 3,624,945, of Dec. 7, 1971, which not only blocks access to the trigger, but also severely restricts any motion by the trigger while the lock is installed on a revolver.